diff options
authorGuanXuetao <>2011-01-15 18:08:09 +0800
committerGuanXuetao <>2011-03-17 09:19:05 +0800
commit7f509a9ef7af0d6ac852d49eb87ed2b9857821cc (patch)
parent38f5bf84bd588a82890f5ab32cba3317555a73e1 (diff)
asm-generic headers: add arch-specific __strnlen_user calling in uaccess.h
This patch changes the implementation of strnlen_user in include/asm-generic/uaccess.h. Originally, it calls strlen() function directly, which may not correctly handle the access of user space in most mmu-enabled architectures. New __strnlen_user is added for using as an architecture specific function. Signed-off-by: Guan Xuetao <> Reviewed-by: Arnd Bergmann <>
1 files changed, 5 insertions, 3 deletions
diff --git a/include/asm-generic/uaccess.h b/include/asm-generic/uaccess.h
index b218b8513d04..ac68c999b6c2 100644
--- a/include/asm-generic/uaccess.h
+++ b/include/asm-generic/uaccess.h
@@ -288,14 +288,16 @@ strncpy_from_user(char *dst, const char __user *src, long count)
* Return 0 on exception, a value greater than N if too long
-#ifndef strnlen_user
+#ifndef __strnlen_user
+#define __strnlen_user strnlen
static inline long strnlen_user(const char __user *src, long n)
if (!access_ok(VERIFY_READ, src, 1))
return 0;
- return strlen((void * __force)src) + 1;
+ return __strnlen_user(src, n);
static inline long strlen_user(const char __user *src)